Polyether copolymer, solid polymer electrolyte and battery

Abstract

A solid polymer electrolyte containing a polyether copolymer having a weight-average molecular weight of 104 to 107 which may optionally be cross-linked and which contains(A) 1 to 99% by mol of a repeating unit derived from a monomer represented by the formula (I): wherein R1 represents a divalent organic group,(B) 99 to 1% by mol of a repeating unit derived from ethylene oxide, and(C) 0 to 15% by mol of a repeating unit derived from a monomer having one epoxy group and at least one reactive functional group, an electrolyte salt compound, and a plasticizer has an excellent ionic conductivity.

What is claimed is:  
     
       1. A polyether copolymer having a weight-average molecular weight of 10 4  to 10 7  which may optionally be cross-linked and which comprises: 
       (A) 1 to 99% by mol of a repeating unit derived from a monomer represented by the formula (I):                    
        wherein R 1  represents a divalent organic group selected from the group consisting of  
       —CH 2 —O—(CHA 1 —CHA 2 —O) n —CH 2 —,  
       —CH 2 —O—(CH 2 ) n —,  
       —CH 2 —O—(O)C—(CH 2 ) n —,  
       —(CH 2 ) m —CO 2 —(CH 2 ) n —, and  
       —(CH 2 ) m —O—CO 2 —(CH 2 ) n —,  
       wherein A 1  and A 2  each is hydrogen or a methyl group, n is a number of from 0 to 12 and m is a number of from 0 to 6,  
       (B) 99 to 1% by mol of a repeating unit derived from a monomer represented by the formula (II):                    
        and  
       (C) 0 to 15% by mol of a repeating unit derived from a monomer having one epoxy group and at least one reactive functional group.  
     
     
       2. The polyether copolymer of claim  1 , wherein the group R 1  in the formula (I) is 
       —CH 2 —O—(CHA 1 —CHA 2 —O) n —CH 2 —,  
       —CH 2 —O—(CH 2 ) n —, or  
       —CH 2 —O—(O)C—(CH 2 ) n —,  
       wherein A 1  and A 2  each is hydrogen or a methyl group, and n is a number of from 0 to 6. 
     
     
       3. The polyether copolymer of claim  1 , wherein the reactive functional group in the repeating unit (C) is (a) a reactive silicon group, (b) an epoxy group, (c) an ethylenically unsaturated group, or (d) a halogen atom. 
     
     
       4. The polyether copolymer of claim  3 , wherein the monomer having a reactive silicon group which constitutes the repeating unit (C) is 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 4-(1,2-epoxy)butyltrimethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. 
     
     
       5. The polyether copolymer of claim  3 , wherein the monomer having two epoxy groups which constitutes the repeating unit (C) is 2,3-epoxypropyl-2′,3′-epoxy-2′-methylpropyl ether or ethylene glycol-2,3-epoxypropyl-2′,3′-epoxy-2′-methylpropyl ether. 
     
     
       6. The polyether copolymer of claim  3 , wherein the monomer having an ethylenically unsaturated group which constitutes the repeating unit (C) is allyl glycidyl ether, 4-vinylcyclohexyl glycidyl ether, α-terpinyl glycidyl ether, cyclohexenylmethyl glycidyl ether, p-vinylbenzyl glycidyl ether, allylphenyl glycidyl ether, vinlyl glycidyl ether, 3,4-epoxy-1-butene, 3,4-epoxy-1-pentene, 4,5-epoxy-2-pentene, 1,2-epoxy-5,9-cyclododecadiene, 3,4-epoxy-1-vinylcyclohexene, 1,2-epoxy-5-cyclooctene, glycidyl acrylate, glycidyl methacrylate, glycidyl sorbate, glycidyl cinnamate, glycidyl crotonate or glycidyl-4-hexenoate. 
     
     
       7. The polyether copolymer of claim  3 , wherein the monomer having a halogen atom which constitutes the repeating unit (C) is epibromohydrin or epiiodohydrin. 
     
     
       8. The polyether copolymer of claim  1 , which comprises 10-95% by mol of the repeating unit (A), 90-5% by mol of the repeating unit (B), and 0-10% by mol of the repeating unit (C). 
     
     
       9. A solid polymer electrolyte which comprises: 
       (1) a polyether copolymer of claim  1 ,  
       (2) an electrolyte salt compound, and,  
       (3) optionally present, a plasticizer selected from aprotic organic solvents and esters, ethers or metal salts of linear or branched polyalkylene glycols having number-average molecular weights of 200 to 5,000 or metal salts of said esters or ethers.  
     
     
       10. The solid polymer electrolyte of claim  9 , wherein the electrolyte salt compound (2) comprises a cation selected from metal cations, ammonium ion, amidinium ion, and guanidium ion, and an anion selected from chloride ion, bromide ion, iodide ion, perchlorate ion, thiocyanate ion, tetrafluoroborate ion, nitrate ion, AsF 6   − , PF 6   − , stearylsulfonate ion, octylsulfonate ion, dodecylbenzenesulfonate ion, naphthalenesulfonate ion, dodecylnaphthalenesulfonate ion, 7,7,8,8-tetracyano-p-quinodimethane ion, X 1 SO 3   − , [(X 1 SO 2 )(X 2 SO 2 )N] − , [(X 1 SO 2 )(X 2 SO 2 )(X 3 SO 2 )C] − , and [(X 1 SO 2 )(X 2 SO 2 )YC] − , wherein X 1 , X 2 , X 3  and Y each is an electron-attractive group. 
     
     
       11. The solid polymer electrolyte of claim  9 , wherein X 1 , X 2  and X 3  each is independently a perfluoroalkyl group having 1-6 carbon atoms or a perfluoroaryl group having 6-18 carbon atoms, and Y is a nitro, nitroso, carbonyl, carboxyl, or cyano group. 
     
     
       12. The solid polymer electrolyte of claim  9 , wherein the metal cation is the cation of a metal selected from Li, Na, K, Rb, Cs, Mg, Ca, Ba, Mn, Fe, Co, Ni, Cu, Zn, and Ag. 
     
     
       13. The solid polymer electrolyte of claim  9 , wherein the aprotic organic solvent is an aprotic organic solvent selected from ethers or esters. 
     
     
       14. The solid polymer electrolyte of claim  9 , wherein the aprotic organic solvent is an organic solvent selected from propylene carbonate, γ-butyrolactone, butylene carbonate, 3-methyl-2-oxazolidone, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether. 
     
     
       15. The solid polymer electrolyte of claim  9 , wherein the polyalkylene glycol is polyethylene glycol or polypropylene glycol. 
     
     
       16. The solid polymer electrolyte of claim  9 , wherein the derivative of polyalkylene glycol is an ether derivative or an ester derivative. 
     
     
       17. The solid polymer electrolyte of claim  9 , wherein the metal salt of polyalkylene glycol is any one of a sodium salt, a lithium salt, and a dialkylaluminum salt. 
     
     
       18. A battery comprising a solid polymer electrolyte of claim  9 , a cathode and an anode.